So that brings us to a new peer-reviewed paper published this week in the Proceedings of the National Academy of Sciences. This study took direct measurements of 489 shale-gas wells being drilled around the United States — a far more detailed look than had been done before. (The study was conducted by the University of Texas and funded by both the Environmental Defense Fund and nine oil and gas firms, including Shell and Chevron.)
The study concluded that the methane leakage rates from these wells were fairly low — lower, in fact, than the EPA's estimates. The EPA had estimated that about 1.2 million tons of methane were probably seeping out of these wells. But the researchers found that only around 957,000 tons of methane were coming out.
What's more, the study found that new techniques required by the EPA to capture methane after wells have been drilled were very effective at minimizing certain leaks. (These techniques are known as 'green completions.') By contrast, other parts of the production process not regulated by the EPA, such as valves and chemical pumps, were leaking more methane than previously thought.
The rest of the article points out the caveats and they're significant. I think the better headline would imply that it's possible that fracking can avoid a lot of methane leaks, but we're not doing it right all the time.